Accept that tiers are different. And have them actually scale.
That's a good suggestion.
Another one:
Recognize that the fighter class is doing A LOT of heavy lifting and offer some alternative mythic, high fantasy, etc. suggestions that are more than joe average fighter - possibly in the DMG. Realistically, this kind of thing is more begging for 3rd party support (which is more likely) but I bet WoTC could do pretty well putting out (for ex.) a Bo9S equivalent for 5e.